Internal combustion engine



July 26, 1932. J. G. VINCENT ,1

' INTERNAL COMBUSTION ENGINE Filed March 5, 1928 :2 Sheets-Sheet I Jul ze, 1932.

J. G. VINCENT INTERNAL COMBUSTION ENGINE Filed March 5, 1928 2 Sheets-Sheet 2 L/EEEE E TZZNQENY:

Patented July 26, 1932 UNITED STATES PATENT. OFFICE J'ESSE G. VINCENT, OF DETROIT, MICHIGAN, ASSIGNOR TO PACKARD MOTOR CAR COM- PANY, OF DETROIT, MICHIGAN, 'A CORPORATION OF MICHIGAN INTERNAL COMBUSTION ENGINE Application filed March 3,

This invention relates to internal combustion engines and more particularly to carburetors therefor.

In order to increase the power and speed normally developed by an internal combustion engine of given dimensions at intervals only during the operation of the engine, intermittent supercharging is sometimes employed. With this method, the explosive mixture or charge is forced into the engine cylinders at a pressure greater than atmospheric by means of a supercharging pump or blower arranged to force air under pressure into the air intake of the carburetor at desired intervals during the operation of the engine. However, the type of carburetor generally used with internal combustion engines is provided with a fuel nozzle designed to supply the proper quantity of fuel to the carburetor mixing chamber only during normal operation of the engine, and such nozzle is commonly incapable of supplying the necessary additional quantity of fuel to the mixing chamber to provide the richer mixture or charge required for the engine cylinders during supercharged operation. This is particularly true in the type of carburetor designed to provide a leaner mixture to the engine cylinders at the higher engine speeds.

Consequently, in order that a properly proportioned explosive mixture or charge will be supplied to the engine cylinders during both normal and supercharged operation of the engine, a modification of the usual type of carburetor, particularly the fuel nozzle thereof, is desirable.

It is an object of the present invention to provide a carburetor for use with an intermittently supercharged internal combustion engine adapted to supply a properly proportioned explosive mixture or charge to the engine cylinders during both normal and supercharged operation.

Another object of the invention is to provide a carburetor for use with an intermittently supercharged internal combustion engine adapted to automatically increase the quantity of fuel delivered to the mixing so chamber when the supercharging blower is 1928. Serial No. 258,817.

started to supply the necessary richer mixture required-for supercharged operation.

Another object of the invention to provide a carburetor for use with an intermittently supercharged internal combustion engine adapted to supply a predetermined larger quantity of fuel to the mixing chamber of the carburetor during supercharged operation as compared with the quantity of fuel delivered to the mixing chamber during normal operation of the engine.

Another object of the invention is to provide a carburetor for use with an intermittently supercharged internal combustion engine adapted to automatically increase proportionally the quantity of fuel supplied to the mixing chamber as the pressure and quantity of air from the supercharging blower increases so that a properly proportioned explosive mixture will be supplied to the engine cylinder during normal operation and during all stages of supercharged operation.

Other objects of the invention will appear from the following description taken in connection with the drawings forming a partof this specification, in which:

Fig. 1 is a View, partly in section and part1 in elevation of a carburetor embodying he invention, showing the relation of the parts for normal operation of the engine;

Fig. 2 is a fragmentary sectional view of the form disclosed inFig. 1 showing the relation of the parts for supercharged operation of the engine; I

Fig. 3 is a View similar to Fig. 1 showing 5 another form of the invention and the relation ofthe parts for normal operation of the engine; a

'Fig. 4' is a fragmentary sectional view of the form disclosed in Fig. 3 showing the relation of the parts for supercharged operation of the engine, and

Fig. 5 is a diagrammatic View of an internal combustion engine associated with a supercharger, showing the application of this invention thereto.

Referring to the drawings, in Fig. 5 is shown an internal combustion engine indicated generally at 6, having an intake manifold and provided with a supercharger 7 which may conveniently be of the rotary blower type. The supercharger is adapted to be driven from the engine crank shaft through any appropriate gearing (not shown), including a clutch indicated at 8 by which the supercharger may be connected to the engine in driving relation or disconnected therefrom at the will of the engine operator. The supercharger is provided with an air discharge pipe 9 which leads to and communicates with the main air inlet 15 of the engine carburetor 10. The carburetor 10 is adapted to be connected to the engine intake manifold at 11 and fuel is supplied to the carburetor through a fuel pipe 12, connected at 13 to a float chamber 14. The main air inlet 15 of the carburetor is controlled by a butterfly valve 16 actuated by suitable mechanism 17 and the auxiliary air intake 18 is controlled by a spring loaded valve, the spring and stem of which are housed in a cover 19. Air entering the main air intake 15 is drawn through a spray mixing tube 20 into a mixing chamber 21 and a throttle valve 22 actuated by suitable mechanism is adapted to control the quantity of explosive mixture or charge entering the intake manifold. A fuel nozzle 23 supplies fuel to the mixing tube 20 and in'the usual internal combustion engine carburetor, this nozzle communicates at its lower end with a passage 25 adapted to convey fuel from the float chamber to the fuel nozzle. In accordance: with the present invention, however, this construction has been modified so that an increased quantity of fuel is automatically supplied to the mixing chamber when the supercharging blower is connected to the engine to provide the required richer mix- ,ture necessary for supercharged operation.

In the form disclosed in Figs. 1 and 2, fuel nozzle 23 provided with} an axial passage 24 having a metering portion 24 is threaded or otherwise secured to the carburetor body. The enlarged lower end of the nozzle forming a head 26, is axially counterbored as at 27 and the annular shoulder formed at the juncture of the municating at their inner ends with counter bore 27 and at the outer end of the counterbore a valve guide member 31 in the form of an apertured disk is secured to the head 26 in any suitable manner as by swaging or the like.

Below the main air inlet 15 and concentric with fuel nozzle 23, the carburetor body is provided with an annular flange 32 preferably formed integrally with the carburetor body and threaded or otherwise secured to this flange 32 is a cylindrical casing 33 provided with an opening in its lower end into which is threaded a plug 34 having a cylincylindrical wall 38 and relatively fixed and 4 movable end walls 39 and 40. End wall 39 is rovided with a central opening 41 through w ich fuel from the float chamber is adapted to enter the bellows as will presently appear and is secured in fixed position between the carburetor body and casing 33 with suitable gaskets interposed to provide a tight joint. End wall 40 has an inwardly projecting cylindrical portion 42, to the end wall 43 of which is'mounted a'valve 44 suitably secured thereto as by nuts 45 threaded on the valve and turned up against both sidesof the end wall 43. I

As shown, the valve 44 is. of cylindrical form and. is axiallydrilled at its upper end to provide a passage 46 preferably of smaller cross-sectional area than the metering portion 24 of nozzle passage 24, and is radially drilled at spaced points about its cylindrical wall at a short distance from its upper end to provide a series of passages 47 communicating with passage 46. Theupper end of the valve is suitably beveledto snugly fit valve seat 29 and guide member 31 prevents excess lateral movement of the valve relative to its seat. An elongated cylindrical guide member 48, preferably an extension of valve 44, engages guide 36 in plug 35 and with guide member 31 assures proper alignment of the valve. A coil spring 49 between end wall 43 and cylindrical casing 33 yieldingly presses valve 44 against its seat.

A pipe 80 connected at one end to the supercharging blower outlet is connected to the upper part of float chamber 14 by a. suitable connection 81 and communicates the pressure of the air entering the mixing chamber of the carburetor" to the float chamber above the fuel contained therein. With this arrangement. it will be apparent that the identical ressure of the air entering the mixing cham er from the supercharger will be acting above the fuel in the float chamber at all stages of supercharged operation, that is to s'ay,.at all speeds of the engine while the supercharging blower is in operation.

From the foregoing description, the operation of the device will be evident. During normal operation of the engine or during operation with the supercharging blower disconnected from the engine, air will enter the carburetor and the mixing chamber at atmossame as the level in the float chamber, the fuel entering the nozzle through radial passages 30, counterbore 27 and passages 47 and 46 in the valve 44. Since the valve 44 is seated and since passage 46 is smaller in cross-sectional area as compared with the metering portion 24 of fuel nozzle passage 24, during normal or unsupercha-rged operation of the engine, passage 46 in valve 44 will determine the quantity of fuel supplied to mixing tube 20 and mixing chamber 21. Valve passage 46 thus is the normal metering passage for the fuel nozzle or the metering passage of the fuel nozzle during normal or unsupercharged operation of the engine.

However, as soon as the supercharging blower is connected to the engine, the pressure of the air delivered to the mixing chamber by the supercharger will be communicated to the float chamber and the pressure of the fuel in bellows 37 will cause the bellows to expand and move end wall 40 downwardly and thus move valve 44 off its seat. In this inoperative position of the valve, shown in Fig. 2, passage 46 is no longer effective as, a metering passage, since the fuel entering the fuel nozzle is not forced to pass through passage 46. Larger metering passage 24 of the fuel nozzle therefore functions as the metering passage during supercharged operation to govern the quantity of fuel delivered to the mixing chamber. In this way, a larger quantity of fuel is automatically delivered to the mixing chamber when the supercharging blower is started to mix with the air forced into the carburetor by the supercharging blower and to provide the richer mixture necessary for supercharged operation. Valve 44 will be held off its seat and the larger quantity of fuel will be continued to be delivered to the mixing chamber until the blower is disconnected from the engine, at which time the pressure will be removed from the float chamber and the bellows. With the pressure removed, spring 49 will press valve 44 into operative position against its seat and passage 46 will again function as the metering passage for the fuel nozzle. It is advisable to limit the expansion of the bellows and in this instance it will be noted that the expansion is limited by the engagement of end wall 40 ofthe bellows with casing 33 as shown in Fig. 2.

The form of the present invention disclosed in Figs. 3 and 4 is shown as adapted to the same type of carburetor disclosed in Figs. 1 and 2 and in both forms like reference characters refer to like parts. Referring to Figs. 3 and 4, fuel nozzle 50, threaded or otherwise secured to the carburetor body, is provided with a fuel passage 51 having a metering portion 52. The carburetor body has an annular flange 53 preferably formed integrally therewith and threaded or otherwise secured to this flange by an integral boss 54 is an annular casing member 55. A cover 56 having a plurality of apertures 57 and a projecting boss 58 is bolted or otherwise secured to casing member 55 and se cured between casing member 55 and cover 56 is a circular corrugated diaphragm 59 made liquid tight with the casing member 55 by a suitable gasket 60.

' A needle valve 61 having a conical metering head 62 and a flange 63 is mounted centrally of diaphragm 59 with flange 63 abutting the diaphragm and secured thereto in any suitable manner as by riveting over the end 64 of the valve against a suitable washer 65. Valve 61 has an annular flange preferably formed integrally therewith providing a stop 66 adapted to abut the skirt 67 of fuel nozzle 50 and this stop 66 is provided with a series of small passages 68 arranged about the needle valve 61. A coiled spring 69 mounted between diaphragm 59 and cover 56 yieldingly presses the needle valve into the fuel nozzle until stop 66 abuts skirt 67, and a bolt 70 threaded into boss 58 and held in adjusted position by a lock nut 71 provides a stop to limit downward movement of the needle valve. As shown, the needle valve 61 is provided with suitable guide members 72 adapted to engage the walls of fuel passage 51 to maintain the central position of the valve in the nozzle.

The operation of this form of the device is very similar to the operation of the form heretofore disclosed. During normal operation of the engine with the supercharging blower disconnected, substantially atmospheric pressure will exist on both sides of diaphragm 59 and needle valve 61 will be pressed upwardly into fuel nozzle 50 by spring 69 until stop 66 engages skirt 67 as shown in Fig. 3. Fuel from the float chamber will enter the fuel nozzle through passage 25 and passages 68 in stop 66 and the quantity of fuel entering the mixing tube 20 and mixing chamber 21 to mix with the air therein will be determined by the cross-sectional area of the annular metering passage surrounding metering head 62 of the needle valve. But when the supercharging. blower is connected to the engine,

the pressure transmitted to the float chamber through pipe will be communicated to the diaphragm 59 through the fuel in casing member 55 above the diaphragm. This pressure will flex the diaphragm downwardly and move the needle valve downwardly with the diaphragm and thus increase the cross-sectional area of the annular metering passage of the fuel nozzle. In this way a larger quantity of fuel is automatically supplied to the mixingchamber as soon as the supercharger is connected to the engine to provide the richer mixture necessary for supercharged operation and this increased quantity of fuel will be supplied as long as the supercharging blower is connected to the engine. It will be noted that the flexing or deformation of the diaphragm will be proportional to the pressure developed by the supercharging blower and that as the pressure and volume of air forced into the carburetor increases, the amount of fuel supplied to the mixing chamber to mix with the air will increase until the valve abuts stop 64 as shown in Fig. 4, when the metering passage is of maximum area. As soon as the supercharging blower is disconnected from the engine, the pressure in the float chamber and on the diaphragm will be relieved and spring 69 will press needle valve 61 back into the position occupied for the normal operation of the engine.

Thus is provided a carburetor for use with an intermittently supercharged internal combustion engine capable of supplying at all times during both normal and supercharged operation. a properly proportioned mixture to the cylinders of the engine. The carburetor automatically adjusts itself to provide the necessary richer mixture immediately upon the initiation of and during the supercharged operation and automatically readjusts itself to supply the leaner or normal mixture required for normal operation as soon as the supercharging blower is dis-' connected from the engine. a

It will be understood that various forms of the invention other than those described above may be used without departing from the spirit or scope of the invention.

Having thus described my invention. what I claim and desire to secure by Letters Patent 1s:

1. In an internal combustion engine adapted to be supercharged by a blower arranged for connection to-and disconnection from the engine, a carburetor having a mixing chamber and a float chamber, a nozzle for supplying fuel to the mixing chamber and connected with the float chamber, a valve for the nozzle. and a flexible member for operating the valve, said flexible member being responsive to pressure above atmospheric pressure applied to the float chamber.

2. In a carburetor having a mixing chamber and a float chamber, a nozzle for supplying fuel to the mixing chamber and connected with the float chamber, a valve for the nozzle. and a flexible member yieldingly pressed in one direction for operating the valve, said flexible member being adapted to be flexed within limits upon application of pressure above atmospheric pressure to the float chamber.

3. In an internal combustion engine adapted to be supercharged by a blower arranged for connection to and disconnection from the engine, in combination, a carburetor having a nozzle for supplying fuel to the mixing chamber of the carburetor, a valve controlling the quantity of fuel supplied to the mixing chamber by the nozzle,

a pressure responsive flexible member in compared with the nozzle passage, the valve passage being adapted to communicate with the nozzle passage with the valve in operative position and adapted to be spaced from and out of communication with the nozzle passage with the valve in inoperative position and flexible means responsive to pressure above atmospheric for moving the valve into inoperative position.

5. In a carburetor, a nozzle for supplying fuel to the mixing chamber of the carburetor, a valve cooperating with the nozzle having apassage of diflerent cross-sectional area as compared with the nozzle passage, the valve passage being adapted to communicate with the nozzle passage with the valve in operative position, a bellows responsive to pressure above atmospheric for moving the valve into inoperative position out of communication with the nozzle passage and yielding means for moving the valve to operative position.

6. In a carburetor, a nozzle for supplying fuel to the mixing chamber of the carburetor, a. valve cooperating with the nozzle having a passage of smaller cross-sectional area as compared with the nozzle passage, said valve adapted to be operated by a bellows in communication with the float chamber of the carburetor to move the valve from operative position with the valve passage in communication with the nozzle passage to inoperative position with the valve spaced from the nozzle passage.

7. In a carburetor, a nozzle for supplying fuel to the mixing chamber of the carburetor, a valve cooperating with the nozzle having a passage of smaller cross-sectional area as compared with the nozzle passage, said valve adapted to be yieldingly pressed to operative position with the valve passage in communication with' the nozzle and to be moved to inoperative position with the valve spaced from the nozzle by a bellows arranged to respond to pressure applied to the float chamber of the carburetor.

8. In a carburetor, a nozzle for supplying fuel to the mixing chamber of the carburetor, a valve cooperating with the nozzle having a passage of smaller cross-sectional area as compared with the nozzle passage, said valve being carried by a bellows arranged to receive fuel from the float chamber of the carburetor and to be yieldingly pressed into operative position with the valve passage in direct communication with the nozzle passage, said bellows adapted to expand upon the application of pressure to the float chamber and to move the valve to inoperative position with the valve spaced from the nozzle.

9. A carburetor for an internal combustion engine adapted to be supercharged by a blower arranged for connection to and disconnection from the engine, comprising a nozzle for supplying fuel to the mixing chamber of the carburetor, a valve having a passage of smaller cross-sectional area as compared with the nozzle passage adapted to cooperate with the nozzle, said valve being carried by a bellows connected with the float chamber of the carburetor, means for yieldingly pressing the valve into operative position with the valve passage in direct communication with the nozzle passage, said valve being adapted to be moved into inoperative position with the valve spaced from the nozzle by the expansion of the bellows when the blower is connected to the engine and the blower pressure communicated to the float chamber, whereby for normal operation of the engine with the blower disconnected therefrom, the valve passage is the fuel metering passage for the carburetor and with the blower connected to the engine, the nozzle passage is the fuel metering passage.

10. A carburetor having a mixing chamber and a float chamber, a nozzle for supplying fuel to the mixing chamber and connected with the float chamber, a valve for the nozzle having a passage of difierent cross sectional area than that of the nozzle passage, and a flexible member to move the valve from operative position with the valve passage in communication with the nozzle passage to inoperative position with the valve spaced from the nozzle passage and out of communication therewith, said flexible member being responsive to pressure above atmospheric pressure applied to the float chamber.

In testimony whereof I aflix m signature.

JESSE G. NCENT. 

